开缝压电圆环深海水听器

利用能量法得到了开缝压电圆环水中的谐振频率方程与电导纳曲线;通过构建开缝压电圆环低频接收状态等效电路图,推导了开缝压电圆环低频开路电压灵敏度;比较开缝压电圆环和整体圆环低频接收灵敏度,提出了利用开缝压电陶瓷圆环与溢流结构相结合设计深海水听器的思路;通过建立溢流式开缝压电圆环有限元仿真模型,探讨了开缝压电圆环的低频开路电压灵敏度与圆环结构参数的关系。经过仿真优化,研制了水中谐振频率600 Hz的开缝压电圆环深海水听器。水池声学测试与耐压测试结果表明,溢流式开缝压电圆环水听器在100~300 Hz频段内低频开路电压灵敏度最大值为-193.2 dB,最小值-197.9 dB,起伏-4.7 dB,耐静水压30 MPa;与采用相同尺寸压电元件的溢流圆环水听器相比,溢流式开缝压电圆环水听器的低频开路电压灵敏度提高20 dB;验证了本文提出的采用开缝压电圆环构建深海水听器的实用性。     

MEMS压电水听器和矢量水听器研究进展*

基于微电子机械系统制造技术的MEMS压电水听器和矢量水听器具有小型化、低功耗、低成本、易成阵、无源、噪音低等优点。对基于ZnO薄膜的MEMS水听器和矢量水听器进行了研究,测试结果表明,硅微压电水听器的灵敏度为-192 d B(ref.1 V/μPa),基本达到实用化的要求。MEMS压电矢量水听器等效声压灵敏度为-229.5 d B(ref.1 V/μPa),比同类型压阻式MEMS矢量水听器的灵敏度高17 d B,但还未达到实用化要求。为了进一步提高MEMS矢量水听器的灵敏度,设计了具有U形槽的压电复合悬臂梁结构和电极串联结构,采用具有更高压电系数的掺钒ZnO薄膜作为压电层,并对MEMS制备工艺进行了改进,有望显著提高MEMS矢量水听器的灵敏度。     

Miniature piezoelectric polymer ultrasonic hydrophone probes

The advantages of using piezoelectric polymer (plastic) materials as the sensitive element in miniature ultrasonic hydrophone probes are described, and proposed designs are critically reviewed. A novel needle type of probe design is described in detail, together with calibration results of the sensitivity and directivity of 0.6 mm and 1 mm diameter probes. The former typically have an end of cable sensitivity of ?271 dBV μPa^?1 ± 2 dB between 1 and 10 MHz, the latter of ?264 dBV μPa^?1 ± 1.5 dB. The linearity, temporal stability and thermal stability of those probes are also discussed. They are shown to be small and reliable instruments for obtaining good spatial and temporal resolution in ultrasonic field measurements.     

新型MEMS压电矢量水听器

对一种具有U形槽或双U形槽结构的MEMS压电式矢量水听器进行了仿真分析与优化,采用微机械加工技术研制出水听器芯片,并对芯片进行了封装与性能测试。提出了理论灵敏度和能量综合分析的方法,在考虑杂散电容的情况下,对敏感结构进行了更加精确的优化。从实验结果可以看出,所提出的优化方法比仅考虑理论灵敏度的传统优化方法具有更高的准确度。此外,具有双U形槽结构的矢量水听器的灵敏度比传统的单臂悬臂梁结构的灵敏度高约5.9dB,并且具有良好的指向性。     

灵敏度可调式压电薄膜水听器

本文介绍一种灵敏度可调式压电薄膜水听器，采用PVDF薄膜作为换能材料，聚碳酸脂作为背衬，薄膜粘贴在背衬的内壁，软性的背衬在声压的作用下形变。从而带动薄膜形变，产生电信号输出。水听器内装有前置放大器，调节放大器的负载电阻可调节水听器的灵敏度，灵敏度变化范围为出，水听器内装有前置放大器，100Hz-16kHz。     

ZnO薄膜硅微压电矢量水听器

提出了一种基于ZnO压电薄膜的硅微压电矢量水听器,其核心部件是利用微电子机械系统(MEMS)技术制作的悬臂梁结构压电加速度计。由近似解析和有限元分析,得出加速度计的灵敏度和谐振频率,并在此基础上对其进行了优化设计。研制了MEMS压电加速度计,并装配后构成MEMS矢量水听器。测试结果表明:加速度灵敏度在20~1,200 Hz范围内约为0.83 mV/(m/s²)。经过液柱法测量,在1 kHz时,MEMS矢量水听器等效声压灵敏度为-229.5 dB (ref.1V/μPa),比同类型压阻式MEMS矢量水听器的灵敏度高17 dB以上。     

Miniature photonic-crystal hydrophone optimized for ocean acoustics

This work reports on an optical hydrophone that is insensitive to hydrostatic pressure, yet capable of measuring acoustic pressures as low as the background noise in the ocean in a frequency range of 1 Hz to 100 kHz. The miniature hydrophone consists of a Fabry-Perot interferometer made of a photonic-crystal reflector interrogated with a single-mode fiber and is compatible with existing fiber-optic technologies. Three sensors with different acoustic power ranges placed within a sub-wavelength sized hydrophone head allow a high dynamic range in the excess of 160 dB with a low harmonic distortion of better than -30 dB. A method for suppressing cross-coupling between sensors in the same hydrophone head is also proposed. A prototype was fabricated, assembled, and tested. The sensitivity was measured from 100 Hz to 100 kHz, demonstrating a sound-pressure-equivalent noise spectral density down to 12 μPa/Hz(1/2), a flatband wider than 10 kHz, and very low distortion.     

聚（偏二氟乙烯-三氟乙烯）压电圆管水听器

提出了高灵敏度压电共聚物圆管水听器设计方法,论述了聚(偏二氟乙烯-三氟乙烯)[P (VDF-TrFE)]材料结构与压电特性的关系,利用解析法和有限元法,分析了多振动模式耦合特性对压电共聚物圆管水听器灵敏度响应的影响规律,仿真分析了圆管水听器的耐静水压特性和噪声特性,与相同结构的压电陶瓷和压电均聚物水听器相比,压电共聚物圆管水听器低频段灵敏度分别可提高20 dB和5 dB以上,研制了尺寸为Φ14 mm × 55 mm的压电共聚物圆管水听器样品,经测试,在10 Hz~1 kHz频段内水听器灵敏度响应达到-181.8 dB±1 dB,等效自噪声压低于零级海况海洋环境噪声,与理论模型结果有良好的一致性。结果表明,该设计显著提升了圆管水听器的低频接收灵敏度,并为其耐静水压性能提升提供了思路。     

基于球形压电陶瓷的耐压水听器

利用球形压电陶瓷自身所具有的耐压能力,采用径向极化空气背衬压电球壳换能器作为声学接收敏感元件,设计并制作了一种球形耐压水听器。首先对其低频开路接收灵敏度和谐振频率等声学特性进行了分析和有限元仿真,然后对其强度和稳定性等耐压性能进行了分析和有限元仿真,最后对其声学性能和耐压能力进行了测试。测试表明,该球形耐压水听器的直径为36 mm,工作频段为50 Hz～10 kHz,低频接收灵敏度为-198.4 dB (0 dB=1 V/μPa),等效自噪声谱级为46.5 dB@1 kHz,其耐压深度可达3000 m。该耐压水听器为大深度水听器设计提供了参考,在深水声学领域具有重要的应用价值。     

Slotted microcavity ring resonators for optical storage applications

In this paper, slotted microcavity ring resonators based optical storage devices are proposed and analyzed by means of multiresolution time domain technique. The effect of the structure geometrical parameters on the coupling efficiency, normalized transmission spectra and quality factor has been thoroughly investigated and compared to that of the conventional no-slot microring resonator. The suggested slotted configurations increase the quality factor at a fixed gap size between the central ring and input/output waveguides. In addition, the desired compromise between the coupling efficiency and resonance effect inside the ring can be achieved by mere optimization of the slot geometrical characteristics.     

液腔耦合高灵敏度压电陶瓷水听器

提出一种利用液腔模态提高接收灵敏度的压电陶瓷标量水听器,称为液腔耦合水听器。该水听器用径向极化的压电陶瓷圆管作为敏感材料,将圆管的外侧壁和上下端面屏蔽而仅使其内侧壁接收声压信号。用\     

Use of the piezoelectric hydrophone for detecting infra-low-frequency seismoacoustic fields

A possibility of using piezoelectric sound detectors to record infra-low-frequency wave fields is demonstrated. A device for measuring seismoacoustic fields with frequencies 0.01 Hz and lower is developed. The bench tests of the hydrophone showed correctness of the technical approaches used.     

光纤阵与压电阵的海试比较

为了检验光纤水听器阵在低频(100Hz~1kHz)/甚低频段(100Hz)的测量性能,在南海海试中,我们将一16元光纤阵与16元常规压电水听器阵平行安装在同一基阵框架上并沿舷侧布放,使得两阵受到基本相同的振动干扰。通过单频和宽带脉冲信号的传播实验,对双阵接收信号进行比较。试验结果表明,光纤阵具有更好的抗振动加速度性能,因此在甚低频段检测中具有明显的优势。     

采用双迭片压电敏感元件的同振柱型矢量水听器

介绍一种采用双选片作为压电敏感元件的同振柱型矢量水听器。描述了该矢量水听器的设计方法，并给出所研制该类型水听器的灵敏度和指向性测试结果。     

压电陶瓷水听器加速度响应的有限元分析

本文用有限元法分析了压电陶瓷圆柱形水听器的材料参数与几何尺寸对其加速度响应的影响。针对理论分析，进行了水听器加速度响应实验，实验结果与理论分析基本相符。     

The problem of phasing linear hydrophone arrays lying on a shallow ocean bottom

The problem of phasing linear hydrophone arrays lying on the bottom of the Barents Sea is discussed by using the results of a full-scale experiment. In the experiment, a pulsed pressure source was used as a source of sound and three linear hydrophone arrays positioned at different sites served as receivers. For signals at the array’s apertures, the spatial correlation interval is estimated. Output responses of the arrays are compared with and without allowance for the spatial correlation interval of the sound field.     

厚壁径向极化压电陶瓷薄圆环的研究

本文对厚壁径向极化压电陶瓷薄圆环进行了研究,得出了振子的谐振和反谐振频率的理论方程,并用有限元法分析了和实验测试了径向振动模态,给出了理论、有限元法和实验数据的一个对比。结果表明:本文的理论较为完善,对实际运用有一定的指导意义。     

PVDF水听器加速度响应特性的有限元分析

本文用有限元法分析了压电高聚物PVDF圆柱形水听器的材料参数与几何尺寸对其加速度响应的影响。针对理论分析,进行了水听器加速度响应实验,实验结果与理论分析基本相符。     

Background light measurements in the deep ocean

Summary Ambient light intensities in the ocean at depths between 1500 m and 4700 m near Hawaii Island were measured around the one photoelectron level with 5″ diameter hemispherical photomultipliers. Measurements of count rates above variable thresholds were carried out in ship-suspended and bottom-tethered configurations. The ship-suspended rates show considerable fluctuation and their mean value decreases with depth approximately as exp [−x(m)/877]. The bottomtethered rates are about an order of magnitude lower than the ship-suspended rates and show little fluctuation. The calibration of our instrument indicates an absolute flux at 4700 m depth based on the bottom-tethered measurement of 218 ₋₆₀ ⁺²⁰ photons/cm²·s, which is consistent with calculated intensities due to β-decay electrons from⁴⁰K. The difference in the two cases is attributed to bioluminescence due to environmental stimulation.

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Riassunto Sono state misurate le intensità di luce ambiente nell'oceano a profondità tra 1500 m e 4700 m vicino alle isole Hawaii intorno al livello ad un fotoelettrone con fotomoltiplicatori emisferici di 5″ di diametro. Sono state effettuate le misure delle frequenze di conteggio oltre alle soglie delle variabili in configurazioni appese alla nave e ancorate al fondo. Le frequenze delle configurazioni appese alla nave mostrano una fluttuazione considerevole e il loro valore medio decresce con la profondità come exp [−x(m)/877]. Le frequenze delle configurazioni ancorate al fondo sono circa di un ordine di grandezza inferiore di quelle delle configurazioni appese alla nave e mostrano una piccola fluttuazione. La calibrazione del nostro strumento indica un flusso assoluto a 4700 m di profondità basato sulla misura delle configurazioni ancorate al fondo di 218 ₋₆₀ ⁺²⁰ fotoni/cm²·s, che è consistente con le intensità calcolate dovute al decadimento β degli elettroni da⁴⁰K. Si attribuisce la differenza nei due casi alla bioluminescenza dovuta alla stimolazione ambientale.

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Резюме Измеряются интенсивности свечения окружающей среды в океане на глубинах от 1500 м до 4700 м вблизи Гавайских островов с помощью 5-дюймовых полусферических фотоумножителей. йзмерения скоростей счета выше изменяющихся порогов были проведены в случае подвешенном на корабле и в случае прикрелления ко дну. Интенсивности счета в подвешенном состояиии обнаруживают значительные флуктуации и их средняя величина уменьшается с глубиной приблизительно как ехп [−x(m)/877]. Интенсивности счета в случае прикрепления ко дну примерно на порядок меньше интенсивностей в подвешенном состоянии и обнаруживаут малые флуктуации. Градуировка нашей аппаратуры даст на основе измерений в случае прикрепления ко дну величину абсолутного потока на глубине 4700 м, равную 218 ₋₆₀ ⁺²⁰ фотонов/см² с, которая согласуется с вычисленными интенсивностями, обусловленными электронами β-распада от⁴⁰К. Различия, обнаруженные в двух случаях, приписываются биолюминесценции, связанной с возбуждением окружающеи среды.